Coating apparatus



Filed Jan. 14. 1933 March 5, 1935.

Patented Mar. 5, 1935 "UNITED STATES COATING APPARATUS Ange Gerstenberg,

Frederiksberg, near Copen- Denmark Application January 14, 1933, serial No.

In k January 22, 1932 8 Claims. (01. 257-95) For the purpose of adjusting the thickness of a layer of an emulsion, for instance an emulsion of margarin,'a molten fatty material, soap, chocolate or the like deposited on a rotary surface, use

5 has heretofore been made of adjustably mounted rails of various shapes, or of smoothing rollers, which are disposed near up to the rotary surface,

for instance along a generatrix of the same, andengaged by means such as screws or other suitable adjusting means, adapted to adjust the space between the said rail or roller and the rotary surface to any proper value according to the desired thickness of layer of fatty material deposited on the drum. While the rotary surface ismoving past the rail or smoothing roller concerned, the latter will smooth the layer and strike off any surplus of the substance" applied to the surface, in such a manner that the layer to be treated, for instance by cooling or drying acquires a certain predetermined thickness.

The devicesof this kind heretoforeused are subject to certain drawbacks. For instance, it is very difficult to attain an exactly uniform thickness of the layer of emulsion or the like distributed onthe rotary surfac'e, provided that said surface-which as a rule is the cylindrical surface of a rotary drum-has a small obliquity or eccentricity. As the thickness of the layer to be treated, as by cooling or drying, is very small, viz. a fractional part of a millimetre, even a very small variation of the thickness of the layer may have an appreciable influence onthe quality of the final product, as thecooling, drying or the like intended becomes irregular when the thick- 85 ness of layer is irregular. I

The present invention has for its object to avoid this drawback, and according to the same this result is attained in that the rail serving to regulate the thickness of the layer and disposed along the rotary surface transversely to the direction of motion of same, or the part of the said rail co-oper'ating with the rotary surface, is made resilient or is held against the surface by means of a resilient force generated for instance by springs/a pneumatically operated piston or the like, in such ,manner that the said rail, throughout the side or edge facing the rotary surface, will be resting resiliently against the layer of emulsion or fatty material deposited on the said surface and, while striking off the surplus quantity of the substance, will smooth the layer to a thickness depending on the magnitude of the resilient pressure. 1

Although the invention is hereinafter described as applied to a cooling drum sen ling the purpose of cooling a fatty substance, for instance an emulsion of margarin or the like, it is not limited to such application, but is applicable also to apparatuses for cooling other fatty substances as well as for the purpose of adjusting the thickness of a layer of a fatty substance, for instance soap or an emulsion of chocolate or the like deposited on a rotary heating or drying surface. Inasmuch as the cooling and the heating respectively of the said surface or machines for supplying the heating or cooling fluid to the same, or the means for depositing the fatty substances, onto the rotary surface and the means for removing the cooled or dried'substance therefrom,.do not form any part of the invention, they are not explicitly referred to below nor shown in the drawings. The art and application of such machines will be evidentto anyone skilled in the art.

Further details of the invention will appear from the following: specification taken in connection with the appended drawings, wherein:

Fig. 1 shows, diagrammatically, a cross-section of an apparatus according to the invention'as applied to a rotary cooling drum;

Fig; 2 is a similar cross-section of a modified embodiment of the same;

Fig. 3 diagrammatically represents a side elevation of the construction shown in Fig. 1;-

Fig. 4 is a cross section, similar to the first figure, illustrating another modification; and

Fig. 5 correspondingly illustrates a further a cooling drum, which is supposed to rotate in the direction indicated by the arrow, while t-is a coating device adapted to apply to fatty emulsion,such as margarin or a molten fatty substance, to the cooling surface 0, the said device being formed in known manner as a trough or a channel, one side wall of which is formed by the cooling surface c.

In the constructiorf illustrated by Figs. 1 and 3, the coating device t supportsa rail member a situated along a generatrix on the cooling surface 0, which owing to the action of springs s, one of which is shown in Fig. 1, is held in contact with the cooling surface 0, or rather with the layer of substance 1 deposited thereon. .The rail member a can freely move towards and away from the cooling surface 0, overcoming, inthe last mentioned case, the tension of the springs s.

The pressure at which the springs s'actuate therail member, a is decisive for the thickness 1r of the layer of emulsion having passed member a. The pressure is adjustable by means of adjusting screws b passing through lugs h on the coating device t and bearing against presser shoes k on the ends of the springs s that face away from the drum.

The part of the rail member a that faces the drum surface c may have various shapes, which do not relate to the invention as such but are of known nature. The pressure with which the springs s at on the rail member determine the thickness of the layer 1r, as the same has to be in equilibrium with the pressure ei'rerted by the emulsion layer f against the rail member. The last mentioned pressure depends, besides on the shape of the rail member and the viscosity and adhesion to the drum surface, also on the peripheral speed of the latter, and on the thickness of layer 1r desired. Since for a given drum the thickness of layer is the only varying value, a certain spring pressure on the rail member a will always correspond to a certain definite thickness of layer, i. e. this thickness can conveniently be regulated'by anadjustment of the tension of the springs s.

The device has the advantage that any smaller obliquity or eccentricity of the drum will have no appreciable influence on the thickness of layer 1r, as the rail member will be able to follow freely the motions of the'drum surface due to the eccentricity or the obliquity. Further, by shaping suitably the part of the rail member that faces the drum surface and by properly dimensioning the springs s, the result can be attained that the difference between the maximum and the minimum desirable thickness of layer will correspond to,such a considerable difference in the spring tension that an inaccuracy in the adjustment will only to a very small extent influence the thickness of the layer of emulsion.

The device involves still another advantage, viz. of attaining a uniform cooling, even if the temperature and, thereby, the viscosity of the emulsion filling the trough t might be subject to minor unexpected variations. The pressure exerted on the emulsion layer ,f by the adjustable rail member will in fact cause the thickness of layer 1r to be smaller'the less the emulsion is viscous. Since the viscosity of a givenemulsion decreases with increasing temperature, it will be seen directly that if the temperature of the layer of emulsion increases, the rail member'will smooth the emulsion layer to a reduced thickness 1r, 1. e.

the device will to a certain extent be self-regulating as to minor variations in the temperature of the layer of emulsion or fat applied, so that notwithstanding these variations a certain definite temperature will be attained for the product cooled.

Instead of the helical springs s, other means may be used, for instance a pneumatic device, by means of which the rail member a is held with a resilient pressure against the drum surface or the emulsion layer 1. Each of the springs may for instance be replaced by a piston r, as illustrated in Fig., 4, acting on said rail member and working in a cylinder u filled with air supplied through pipe 1) controlled by valve w, in whichlating member that co-operates with the drum c consists of a resilient .plate d in place of the beforedescribed rail (a), said plate having one bent edge resting against the drum surface c or rather against the emulsion layer I, along a generatrix of the drum, while the plate d is otherwise carried by a supporting rail or member e adapted to rest on and slide along the upper edge of the trough t. The said supporting member can be displaced towards the drum surface by means of adjusting screws b, by means of which the pressure between the plate d and the layer of emulsion f can be regulated similarly to the aforedescribed rail a. The screws b are therefore, in this construction as well as in the one shown in Figs. 1 and 3, fitted with large heads g, by means of which they can be adjusted by hand.

In the constructions described above, the rails a and e are disposed on the coating device, but the intent and scope of the invention will not be transgressed by disposing the said rails on independent supporting members outside of the coating device, which supporting members may be of any suitable nature. The supporting rail a may otherwise be replaced by some other supporting members of suitable shape for the resilient surface d.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. An apparatus regulating the thickness of a layer of a fatty material deposited on a rotary surface, comprising a slidably mounted member disposed along the said surface transversely to the direction of motion of the surface, means supporting said member, means for adjusting the width of the space between said member and the rotary surface, and means for effecting a resilient pressure of the member against the layer of the fatty material deposited on the said surface.

2. An apparatus according to claim 1 wherein the rail is slidably mounted on a coating device serving the purpose of depositing the fatty material on the rotary surface.

3. In combination with a rotary cooling drum for cooling fatty substances such as margarine emulsions, a rail disposed along'the drum surface transversely to its direction of motion, and means for securing a resilient pressure of the rail against a layer of the fatty substance deposited on said rotary surface;

4. An apparatus for regulating the thickness of a layer of fatty material deposited on a rotary surface, comprising in combination a rotary cooling drum'on which the fatty substances such as margarine emulsions is cooled, a rail disposed along the drum surface transversely to the direction of motion of the same, means for adjusting the width of the space between the said rail and the drum surface, and means for securing a resilient pressure of the rail against the layer of the fatty substance deposited on the surface.

5. In combination with a rotary cooling drum for cooling fatty substances, an apparatus for adjusting the thickness of the layer deposited on said surface; said apparatus comprising a slidably mounted rail disposed along said surface transversely to the direction of motion of the same, means supporting said rail, means for adjusting the width of the space between said rail and the rotary surface, and means for securing a resilient pressure of the rail against the layer v mansareprovidedto simportthe rail sothatit is adapted toslide with relation to the cool n drum. 7

"I. Arotarycoolingdrumaceordingtoclaim 5, wherein the rail is slidably mounted on a coating device serving the purpose of depositing the fatty material on the rotary surface.

8. A rotary cooling drum for cooling fatty substances such as margarine emulsions, having a slidably adjustable member disposed along the surface of the drum in such manner that one edge of said member faces the drum, means for resiliently supporting said member in its relation to the drum, and means for adjusting the distance between said edge of the member and the said drum surface. I

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